Ultra Resistance Sports: Importance of Fluid Balance and Electrolytes
Fluid balance and electrolytes are essential for optimal exercise performance and also to maintain health.
Water loss through sweating
Many ultra-endurance athletes seldom meet their fluid needs during exercise. It is important to try to take into account all the factors influencing changes in body weight, in addition to fluid loss, and all sources of water ingress. The increased environmental temperature and humidity can increase the rate of sweating in about 1L/h.
Depending on the individual variation, the type of exercise and intensity, sweat rates may range from extremely low values to more than 3L/h
Overhydration and hyponatremia
Overhydration, though not frequently observed, can also present problems, as the composition of inappropriate fluids. The excessive moisture or fluid needs during exercise long-lasting heat with low or negligible sodium intake can result in reduced performance and sometimes hyponatremia (sodium concentration in very low blood). Therefore, with large fluid intake rates, even just to meet the needs of liquids, sodium intake is vital and a higher concentration in beverages (30 to 50 mmol/L – 1.7 to 2’9g NaCl/L) may be beneficial.
If you take enough fluids during exercise, you can see the reduced performance. Furthermore, sodium is necessary for the recovery period to reduce urine output and increase the rate of restoration of water balance.
Influence of Carbohydrate
The inclusion of carbohydrates in a drink can affect the net rate of water uptake, and it is also important to supplement endogenous reserves as a substrate for exercising muscles during ultra-resistance activity. To improve absorption of water, glucose and/or glucose containing carbohydrates (e.g. sucrose, maltose) at concentrations of 3 to 5% w / v recommended. The carbohydrate concentrations above this may be advantageous in terms of glucose oxidation and maintain exercise intensity, but will have no added benefit and, if hyperosmotic (high water and low solute), actually reduce the net rate of water absorption.
The rate of fluid loss may exceed the capacity of the gastrointestinal tract to absorb fluids. Gastric emptying can be below the rate of fluid loss and, therefore, individual tolerance can dictate the maximum rate of fluid introduction. There is great individual variation in gastric emptying rate and tolerance to higher volumes. Training drinking during exercise and to increase tolerance is recommended.
Improve water absorption
Water, electrolytes, and carbohydrates are essential nutrients for maintaining normal physiological function and optimal exercise performance. As you increase exercise duration and intensity, loss of fluid and electrolyte imbalances and compartmental increase unless losses are compensated by the appropriate jacks. Not only the volume but also the composition is essential to ensure the whole body fluid homeostasis (intracellular and extracellular, vascular and interstitial).
Carbohydrate intake during prolonged exercise can help performance not only by increased oxidation of glucose but also indirectly through better absorption of water.
Fluid and Electrolytes for Health and Performance
With an increasing rate of muscle contraction and a growing mass of active muscles, metabolic demands increase as heat production. Compensatory physiological responses include increased circulation and blood flow redistribution. In particular, increases in blood flow to the muscle and the periphery (skin) and the decrease in abdominal flow (hepatic and portal vein) are observed. Besides these cardiovascular changes, increased sweat production, the evaporation of which provides the most efficient means of heat loss available for humans occurs.
During intense exercise and/or long – term, sweat losses can substantially reduce body water. There is virtually no water storage in the body, with the exception perhaps of water stored in muscle glycogen (which is necessary for the metabolism of glycogen), and in the bladder that is not available to contribute to fluid needs. Also, it increases during exercise mainly through an increase in breathing and liquid evaporation airway. Most experienced water loss during exercise is the result of sweating.
If fluids are ingested in sufficient quantities to compensate for losses of fluid, it is achieved by maintaining cooling endogenous mechanisms. However, if a liquid deficit occurs during exercise, the plasma volume and stroke volume is reduced. The heart rate increases and cardiac output decreases at a given point, due to the inability of the heart rate to offset the reduction in stroke volume, and the core temperature is high.
Fatigue during exercise
In contrast, with fluid intake during exercise, these responses are attenuated. Several authors have shown that blood flow to exercising muscles, decreases with dehydration during exercise. These authors have also shown that fatigue associated with dehydration during exercise is highly correlated with high body temperature. It seems to have an internal body temperature critical in fatigue occurs despite varying the initial body temperature or the rate at which heat storage occurs. However, the threshold is reduced by dehydration during exercise.
Supplements Fluid and Electrolytes
The relative importance of carbohydrate supplements and liquids during exercise may vary as a result of the variation in rates of sweating and carbohydrate utilization. External factors such as environmental conditions, type, intensity and duration of exercise influence these needs.
In cooler conditions, with lower rates of sweating and prolonged exercise of moderate to intense, glycogen stores can become limiting before dehydration is significant. By contrast, in hot and humid conditions, when sweat rates are high, the fluid deficit may limit performance before reserves of carbohydrates become limiting performance.
Sweating not only results in water loss but also loss of electrolytes. Electrolytes, in particular, sodium levels vary drastically in sweat and increases with the increasing speed of sweat and decrease with acclimatization and training adaptation.
The volume of fluid to be ingested must be determined individually and adjusted to tolerance, trying to meet the needs. These individual needs must be evaluated by changes in body weight, correct fluid intake and adjust metabolic body weight loss and metabolic water production where feasible.
Experience before the Competition
Drinks should be tested in training to ensure they do not cause us any problems because if tried in a competition it can make our performance worse if they have not done well.